Often scanned document images are analyzed and decisions are made based on the analysis of the image. Additionally, frequently the image is stored and referenced during further processing rather than using the actual item, particularly if the item is a document.
If the scanned image is not acceptable the user must retrieve the original document and re-scan the image. This significantly reduces the efficiency of the system. Therefore, it is desirable to mitigate problems that can lead to poor images.
A common problem that results in poor images is dust accumulation at the scanner. If the scanner uses a moveable head, the dust simply shows up as a small spot or speck on the image. In contrast, when the scanner incorporates a stationary head and the item travels past the head, the dust shows up as an elongated streak along the length of the document.
Additionally, scanners commonly utilize a guide to guide the documents toward or against a glass plate and the scanner scans the image as the document passes across the plate. One commonly used guide is a black foam or rubber roller that urges the documents toward the plate. During use, such rollers accumulate dust and eventually become lighter, and therefore it becomes more difficult to distinguish the document image from the background. Eventually, the roller needs to be cleaned or replaced.
Accordingly, although many attempts have been made to mitigate the impact of dust and debris adjacent the image, dust and debris remain problem.